Explanation:

 An initial public offering (IPO) is the first time that the stock of a private company is offered to the public. IPOs are often issued by smaller, younger companies seeking capital to expand, but they can also be done by large privately owned companies looking to become publicly traded.

Preference shares, more commonly referred to as preferred stock, are shares of a company’s stock with dividends that are paid out to shareholders before common stock dividends are issued. If the company enters bankruptcy, the shareholders with preferred stock are entitled to be paid from company assets first. Most preference shares have a fixed dividend, while common stocks generally do not.

An American depositary receipt (ADR, and sometimes spelled depository) is a negotiable security that represents securities of a non-U.S. company that trades in the U.S. financial markets. ... ADRs are also traded during U.S. trading hours, through U.S. broker-dealers.

An external commercial borrowing in India to facilitate the access to foreign money by Indian corporations and PSUs (public sector undertakings). ECBs include commercial bank loans, buyers' credit, suppliers' credit, securitised instruments such as floating rate notes and fixed rate bonds etc., credit from official export credit agencies and commercial borrowings from the private sector window of multilateral financial Institutions such as International Finance Corporation (Washington), ADB, AFIC, CDC, etc. ECBs cannot be used for investment in stock market or speculation in real estate.